Wound Battery Electrode Layout for Multi-Tab Connection Accuracy
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Solution Overview
Problem
Existing non-aqueous electrolyte secondary battery designs fail to account for variations in electrode thickness, leading to inconsistent exposed portion positions and reduced battery capacity when attempting to connect multiple tabs to predetermined positions.
Innovation Solution
A non-aqueous electrolyte secondary battery design with a wound electrode assembly where the exposed portion angles of the positive electrode are regulated, with larger angles on the initial winding side and smaller angles on the terminal winding side, allowing for consistent tab connection regardless of electrode thickness variations without compromising battery capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the exposed portions are lengthened to accommodate thickness variation, then the tabs can be connected to predetermined positions, but the mass of the mixture layer is reduced and battery capacity decreases
Solution Approach 1:
The patent applies local quality by making the exposed portions have different lengths at different locations along the winding direction. Specifically, the exposed portions at the initial winding side are longer than those at the terminal winding side. This localized variation in exposed portion length allows the tabs to be connected to predetermined positions despite thickness variation, while minimizing the overall reduction in mixture layer mass compared to uniformly lengthening all exposed portions.
2Reliability
If the exposed portions are made larger to ensure tab connection, then connection reliability improves, but the active material area is reduced
Solution Approach 1:
The patent implements local quality by varying the size of exposed portions based on their position in the winding direction. The exposed portions at the initial winding side are larger to provide sufficient connection area, while those at the terminal winding side are smaller. This localized differentiation ensures reliable tab connection where most needed while preserving active material area in other regions.
Data Source
AI summary
This non-aqueous electrolyte secondary battery comprises: an electrode body in which a positive electrode and a negative electrode are wound with a separator therebetween; an electrolyte; and a cylindrical outer can, wherein the positive electrode has a current collector and a mixed layer laminated on at least a portion of the surface of the current collector, a plurality of exposed parts where the current collector is exposed are formed on the surface of the positive electrode, tabs are connected to the respective exposed parts, and when the rotation angle of the electrode body from a winding start-side end to a winding finish-side end of the exposed parts relative to the winding center is defined as an exposed part angle, the exposed part angle of the exposed parts positioned on the winding start side is greater than the exposed part angle of the exposed parts positioned on the winding finish side.